The Plymouth Duster was one of the last hurrahs of the supercar era. Introduced in 1970, this A-Body featured clean styling, a roomy interior, and several engine options. The biggest of these was Chrysler's LA-series 340 cubic inch powerplants. The 340 had already established itself as a rival to Chevy's 350 and Ford's 351, despite its smaller displacement. The Duster was a great place to showcase it.
In drag racing, however, there is an old adage that says "There is no replacement for displacement." Often, strip-blazing Dusters would get 440s or Hemis under the hood for motivation. But that took away the nice power-to-weight ratio of the original 340 package, and such conversions sometimes proved very impractical for the street. Tony Marculawicz of Westland, Michigan, decided he wanted the best of both worlds. His 340 Duster is street tagged and ready to cruise, but will cut quarter-mile times in the 8-second zone on the track.
"I always liked the Duster body style," says the 31-year-old auto technician. This is the fourth such car he has owned, following '71, '73 and '74 examples. To make things even out, the A-Body pictured here is a '72.
The Duster was created to run in Super Street and King of the Street drag action, one of the most popular forms of racing today. Now part of Hot Rod magazine's Fastest Street Car racing program, Super Street is not like conventional drag racing. For production-built American cars, it is run on a no-breakout, heads-up .400-second Pro Tree format. Entries are limited in the number of performance enhancements they can use (i.e., nitrous oxide, blowers, and so on) and tire options are 10.5-inch slicks or 12-inch DOT treaded tires. Other than that, however, virtually anything goes.
Now, to make a 340 run this quick is going to require some expertise. This ably came from Scott Koffel of Koffel's Place II in Huron, Ohio. Koffel started out with the best block available, a cast-iron R-code piece from Mopar Performance. After giving it the full-race treatment for a stroker crank, Scott prepped a forged-steel Mopar Performance crankshaft and eight Venolia piston/BME rod combinations for the short block. With a compression ratio of 14.0:1 and a maximum rpm of 9,000, the engine now has a final displacement of 401 cubes.
On the top of the block went a set of fully-ported and polished B1 aluminum small-block heads. The 2.12-inch intake and 1.62-inch exhaust titanium valves are actuated by a Cam Dynamics roller outfit that opens the intakes over .700 inches off the seats. The lifters and springs are from Crane, the retainers from Trick Titanium, the rockers from Jesel and the timing set is from Cloyes. The intake is a NASCAR Chevrolet unit adapted to this engine, and fuel and nitrous flow into the cylinders via a Holley 1050 Dominator, BG pumps and an NOS nitrous system. Ed's Welding custom built the headers, which are used in conjunction with a set of DynoMax mufflers. Ignition is accomplished using a Mopar Performance crank trigger, an MP distributor, MSD 7AL box and Champion plugs.
Behind the engine is a Powerglide transmission built by John Kyle, complete with an 8-inch TCI converter that allows the motor to wind up to 5200 rpm before sending the power to the 4.30 ring gear. That, a set of Moser axles, a spool from Strange are housed in a 9-inch Ford differential.
Ed's Welding, also located in Huron, Ohio, did much of the work to the car as well. The cage is built around the 107-inch wheelbase using chrome-moly tubing. Koni shocks and Wilwood disc brakes have been added to the front suspension. Ed's also took care of the tinwork, placing "minitubs" in the rear where the stock wheelwells once were. A four-link, coupled to AVO shocks, helps keep the rear end planted to the track, and a set of Wilwood brakes help the Stroud Parachute slow the car down. Weld rims shod with Goodyear front skinnies and big Mickey Thompson 29.5x10.5 rear slicks are found at the four corners.
The Strip Shop got the call when it came time to make the body look as nice as the car ran. Russ Knepp applied his talents to the paint, laying on a deep sheen of PPG-brand green and black hues. The car is all-steel except for the Glasteck hood and a pair of aftermarket Harwood scoops.
Now it was Tony's turn to do his part. Strapped into the Baja poly driver's seat and monitoring the vital signs via a set of AutoMeter gauges and a big 5-inch-diameter Mopar Performance tach, he pointed the nose of the Duster toward the scoreboards. The year's time and $40,000 invested proved their value beyond a doubt as the car clocked an 8.82-second time slip at 155.82 mph.
Now the car is ready for serious competition. Helping at the track are Koffel himself, and crew support John Hildebrant. These pictures were shot at Koffel's shop, and the search for additional horsepower could eventually make this car the quickest full-bodied, small-block Mopar musclecar on the planet.